One of my favorite Einstein quotes is this: “If you can’t explain it simply, you don’t understand it well enough”. It is quite likely that, like many other quotations attributed to Einstein, he never actually said it but I prefer to believe that he said something at least a bit like it. There are various forms of the quotation: “If you can’t explain it to a six year old, you don’t understand it yourself” or “It should be possible to explain the laws of physics to a barmaid”. I studied Astrophysics at University and I seem to recall testing that last one out quite a bit.
This valuable aphorism doesn’t just apply to explanations of complex issues – this also applies to products – simple design nearly always reflects an intimate understanding of user requirements – the kind of design that makes you think “why didn’t I think of that?” One of the best examples of this is Taulia. They address what is actually a fairly complex set of business issues but they’ve turned their solution into something a kid could explain. Look at this very cool video illustrating their dynamic discounting tools.